Western Arizona: Travelling due west from Arizona towards California, Coronado would encounter a gradual increase in elevation as the terrain rises to the Colorado Plateau. The land would change from the low-lying desert region of the Sonoran Desert to more elevated plateaus and mesas, with elevations ranging from around 2,000 to 4,000 feet above sea level.
Lower Colorado River: If Coronado had followed the course of the Colorado River, he would have encountered lower elevations along the river valley and canyons. The Colorado River flows through the Grand Canyon, which reaches depths of over 6,000 feet, before continuing through lower elevation desert landscapes before reaching the Gulf of California.
Sonoran Desert: A more southerly route directly west from Arizona would have kept Coronado within the Sonoran Desert. This region is characterised by relatively low elevations, with many areas below 1,000 feet above sea level. The Sonoran Desert is known for its hot and dry climate, with diverse desert flora and fauna.
In summary, if Coronado had travelled 150 miles due west from Arizona instead of eastward toward New Mexico, the land elevation he would have encountered would depend on the specific route he took. The terrain would have varied from more elevated plateaus to lower desert regions, based on the topography of the Colorado Plateau, the Lower Colorado River, and the Sonoran Desert.